CrossFit Theory

CrossFit is an evidence-based fitness program. Meaningful statements about safety, efficacy and efficiency — the three most important and interdependent facets of any fitness program — can be supported only by measurable, observable, and repeatable facts, (i.e., data). The CrossFit methodology depends on full disclosure of methods, results and criticisms, and we’ve employed the Internet as our primary means to support these values. CrossFit’s charter is open source, making co-developers out of participating coaches, athletes and trainers through a spontaneous and collaborative online community. CrossFit is empirically driven, clinically tested and community developed.

CrossFit offers the world's most useful definition of fitness: increased work capacity across broad time and modal domains. Capacity is the ability to do real work, which is measurable using the basic terms of physics (force, distance and time). Life is unpredictable (much more so than sport) so real world fitness must be broad and not specialized, both in terms of duration and type of effort (time and modal domains).

The magic is in the movements. All of CrossFit’s workouts are based on functional movements. These are the core movements of life, found everywhere, and built naturally into our DNA. They move the largest loads the longest distances so they are ideal for maximizing the amount of work done in the shortest time (intensity).

By employing a constantly-varied approach to training, these functional movements at maximum intensity (relative to the physical and psychological tolerances of the participant), lead to dramatic gains in fitness. Intensity is essential for results and is measurable as work/time. The more work you do in less time, the more intense the effort.

In implementation, CrossFit is, quite simply, the “sport of fitness.” We’ve learned that harnessing the natural camaraderie, competition and fun of sport or game yields an intensity that cannot be matched by other means. The late Col. Jeff Cooper observed, “the fear of sporting failure is worse than the fear of death.” It is our observation that men will die for points. Using whiteboards as scoreboards, keeping accurate scores and records, running a clock, and precisely defining the rules and standards for performance, we not only motivate unprecedented output, but derive both relative and absolute metrics at every workout. This data has important value well beyond motivation.

While it challenges the world’s fittest, the CrossFit program is designed for universal scalability, making it the perfect application for any committed individual, regardless of experience. We’ve used our same routines for elderly individuals with heart disease and cage fighters one month out from televised bouts. We scale load and intensity; we don’t change programs.

The needs of Olympic athletes and our grandparents differ by degree, not kind. Our hunters, skiers, mountain bike riders and housewives have found their best fitness from the same regimen.